This protocol investigates the maximum tolerated, single intravenous dosage and pharmacokinetics of NSC655649 and evaluates the qualitative and quantitative toxicities of the drug when administered as a bolus infusion every 21 days. NSC655649 is an antibiotic with antitumor properties originally isolated from an actinomycete strain ; the parent compound, Rebeccamycin, has never been tested in humans and NSC655649 is the first of the class to go into clinical trials. The study has been extended until August, 1998, in order to accrue additional subjects.